1. Field of the Invention
This invention pertains to wind-powered vehicles, and more particularly to apparatus for attaching the boom and mast of a wind-powered vehicle.
2. Description of the Prior Art
U.S. Pat. No. 3,487,800 discloses a basic wind-powered sailboard consisting essentially of a hull, a mast, a sail, and a wishbone shaped boom. The boom of a sailboard normally consists of two spars, one on either side of the sail. In the typical sailboard, it is considered desirable to attach the boom to the mast in a manner that allows the mast and boom to pivot as a unit with respect to the hull about a generally vertical axis. The attachment mechanism is frequently referred to as a gooseneck.
Various sailboard goosenecks have been developed. For example, U.S. Pat. Nos. 3,487,800; 4,319,536; and 4,334,488 disclose devices that utilize ropes or tapes to connect the mast and boom. The use of ropes or tapes as attaching means presents several drawbacks. These include the tendency of the ropes or tapes to yield under the forces imposed by the wind, difficulty in loosening them when wet, and frequently the requirements of expert knot tying abilities by the user. The ropes often loosen under use. British Pat. No. 1,551,426 shows a boom which includes an eye for enabling the boom to be connected to the mast. That design does not allow unitary pivotal motion of the boom and mast and therefore is not completely satisfactory. International Pat. No. WO79/01078 illustrates three variations of mast-boom attachment devices. Each of the devices is somewhat deficient in that each requires the manipulation of small components, which may be easily damaged or lost. Further, the number of pieces required by the various designs represent undesirable expense and complexity.
Accordingly, a need exists for apparatus to attach the boom of a wind-powered vehicle to the mast in a manner that enables unitary pivoting of the mast and boom and that is inexpensive, simple, and convenient to use.